Pain intensity and side effects during titration of morphine to cancer patients using a fixed schedule dose...

Considerable dose variations and frequent initial side effects have been postulated during start of morphine treatment to patients with pain caused by malignant disease. However, to our knowledge, only one previous study has reported effective doses in morphine naive cancer patients and no prospective evaluation has compared symptoms before with symptoms during morphine titration.

We recruited 40 cancer patients with uncontrolled pain despite receiving codeine or dextropropoxyphen. Baseline data were obtained for two days before start of morphine titration using a fixed scheduled escalation of immediate-release (IR) morphine. When a stable morphine dose was achieved, IR morphine was replaced with slow-release (SR) morphine in equivalent doses. Intensity of pain and side effects were assessed daily. The daily consumption of morphine, rescue analgesics and rescue antiemetics were registered.

The mean titration time to achieve adequate analgesia was 2.3 days (range: 1-6) using a mean daily morphine dose of 97 mg (range: 60-180). Nausea was unaltered after start with morphine but an increased incidence of vomiting occurred (premorphine period 5%, IR morphine period 29%). Transient sedation delayed dose increment in 9 of the 40 patients but mean sedation scores were unaltered. Constipation scores increased while other side effect scores were unaltered. Eighty-two percent of the patients were satisfied or very satisfied with the pain treatment during introduction of morphine.

In cancer patients with uncontrolled pain on weak opioids, successful titration of morphine is achieved fast, with a three-fold morphine dose variation and with little increase in side effects.